How to use this calculator
Choose the property and enter positive whole numbers.
Formula and method
Prime factorization repeatedly divides by the smallest possible prime. LCM(a,b)=ab/GCF(a,b).
Worked example
84 = 2×2×3×7; GCF(84,30)=6 and LCM=420.
Assumptions and supported scope
Positive safe integers through 1 billion; LCM above the JavaScript safe-integer range is displayed as exact integer text. Factorization uses trial division; 1 is neither prime nor composite. Positive divisors only.
Method references
Method and worked example checked against the calculator implementation. About our methods · Report a correction